Hinged vacuum roll gripper



Feb. 6, 1968 v, s I 3,367,705

' HINGED VACUUM ROLL GRIPPER Filed Aug. 5, 1965 3 Sheets-Sheet 1 F G. I 5

IO w- --a 22 a I /40 INVENTOR VICTOR H. AMES LATTORNEY Feb. 6, 1968 v. H. AMES HINGED VACUUM ROLL GRIPPER 3 Sheets-Sheet 2 Filed Aug. 5, 1965 INVENTOR VICTOR H. 'AMES BY wwx Q ATTORNEY vm R Feb. 6, 1968 v. H. AMEs HINGED VACUUM ROLL GRIPPER Filed Aug. 5, 1965 3 Sheets-Sheet 5 FIG. 6

FIG. 7

FIG. 8

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H R 0 T m V as BY QLTZJRNEY United States Patent 3,367,705 HINGEI) VACUUM ROLL GRIPPER Victor H. Ames, Midlothian, Ill., assignor to Whiting Corporation, a corporation of Illinois Filed Aug. 3, 1965, Ser. No. 476,966 19 Claims. (Cl. 294-64) ABSTRACT OF THE DISCLOSURE A vacuum roll gripper for handling cylindrical objects such as paper rolls is attached to a forklift truck and has several plate members pivotally movable on a frame to conform generally to the surface of the cylindrical object. A suction seal is mounted between each of the adjacent members and a gasket runs around the periphery of the gripper extending over several of the plate members and a suction system provides a suction within the area enclosed by the gasket.

The present invention relates to a vacuum or suction roll gripper, and more particularly to a suction gripper construction for handling rolls of paper or other generally cylindrical objects.

One field in which vacuum, or rather suction, gripper apparatus has found important use is in the handling of large, heavy rolls of paper, such as newsprint or kraft, despite the existence of roll-handling apparatus employing mechanical arrangements. Such suction gripper constructions are commonly provided in the form of attachments for lift trucks or other material handling devices. Because paper rolls and the like are commonly provided in various diameters, suction grippers must be capable of adjustment to a range of diameters in order to be practical and economically justified. Heretofore they have commonly been constructed in the form of a plurality of gripper pads each having a generally perimetric gasket enclosing a suction area or cavity, and mounted in spaced relation to each other by means permitting swinging or other movement so as to be engageable with the respect circumferential surfaces of rolls of different diameters. Separate gripper pads require a considerably greater length or linear extent of sealing gasket for a given total suction area than would a single gripper pad having a single gasket enclosing the same suction area, so that more leakage of air occurs and greater suction capacity is required. A single gripper pad, however, presents problems of adjustment to different roll diameters.

The present invention provides a suction gripper construction for paper rolls and similar generally cylindrically articles, employing a single gripper pad to permit of a minimum gasket length for given suction area, and formed of a number of plate members arranged for relative pivotal movement so as to be adjustable to accommodate rolls of different diameters within a given range. Seal means prevent loss of suction between the edges of adjacent plates. The invention may be employed in a number of different embodiments, certain illustrative ones of which are disclosed herein.

It is the main object of the invention to provide a suction gripper construction for handling generally cylindrical objects such as rolls of paper, employing a single gripper pad to provide a single suction area of desired size to be enclosed by a minimum length of continuous gasket means while being adapted for adjustment to a range of roll diameters.

Other and further objects, advantages, and features of the invention will be apparent to those skilled in the art from the following detailed description, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a fragmentary side elevational view of a ICC fork lifttruck incorporating a suction gripper construction of this invention;

FIGURE 2 is a perspective view of a gripper pad according to the invention, showing the front face thereof;

FIGURE 3 is an enlarged fragmentary plan view showing a detail of the arrangement;

FIGURE 4 is an enlarged sectional view taken sub stantially as indicated by the line 44 in FIG. 1, illustrating one form which the invention may take;

FIGURE 5 is a view similar to FIG. 4, but illustrating another form of the invention;

FIGURE 6 is a view similar to FIGS. 4 and 5, on a reduced scale, illustrating a third form of the invention;

FIGURE 7 is a view similar to FIG. 6, but illustrating a further form of the invention; and

FIGURE 8 is a fragmentary rear elevational view of the mounting arrangement of the construction shown in FIG. 7.

Referring first to FIG. 1, there is shown a suction gripper construction according to the invention, generally designated as 19, mounted on the forward portion of a lift truck generally indicated at 11, having an operators station at the forward portion adjacent a steering wheel 12., supported at its forward portion by front wheels 13 (only one shown), and having an upright assembly 14, which may be tiltable and extensible, mounted over the front wheel 13. A carriage mechanism 15, adapted to have lift forks secured thereto in conventional manner, is mounted on the upright mechanism for vertical movement in known manner. Secured on the carriage 15 as by known bracket 16 and other conventional means is a support plate 17 on which may be mounted upper and lower vacuum reserve tanks 18 and 19, and which suitably supports a rotator plate 20. The plate 20 may be rotated by any appropriate means, a suitable mechanism indicated generally at 21 being that disclosed in William A. Norlander, US. Patent No. 3,198,023, for Carriage Rotating Mechanism for Lift Trucks and the Like, Aug. 3, 1965. This mechanism employs a pair of hydraulic cylinders 22 and 23 secured on the support plate 17 and having piston rods with rack portions for engagement with a pinion, concealed by end cover plate 24, secured on the rotator plate 20.

A mounting structure or base generally indicated at 25 provides for support of the gripper pad on the truck, and includes a gimbal arrangement to allow for off-center roll pickup movement of the gripper pad. The gimbal construction is shown in this instance (FIGS. 1 and 4) as comprising a gimbal frame 25 supported for swinging movement on rotator plate 26 by aligned pivots 27. Pivots 28 provide an axis on which a mounting plate 30 is supported by the gimbal frame for relative swinging movement, the two axes being substantially perpendicular. Other gimbal arrangements of course may be employed to permit relative swinging in any direction between the mounting plate 30 and rotator plate 20.

A gripper pad generally designated 31 is movably supported on the mounting plate 30. As best shown in FIG. 2, the gripper pad comprises a pair of plate members 32 curved on a radius generally corresponding to that of the rolls to be handled by the gripper construction, although the curvature need not be arcuate. Each of the plate members has an edge generally parallel to its axis of curvature, and the plate members are arranged with these edges in opposed spaced and generally parallel relation. A flexible sealing member 33, illustrated in this case as formed of a resilient foamed material such as sponge rubber, is disposed between and extends substantially throughout the length of these edges, being secured thereto as by an appropriate cement. The plate members 32 are hingedly connected along an axis adjacent and substantially parallel to the space between the opposed edges thereof, the hinge means 34 in this case being shown as of the piano type extending through at least a major portion of the length of the plate members, with leaf elements Welded to the inner or concave faces of the plate members on opposite sides of the seal 33. The hinge means 34 are shown as projecting within the concavity of the gripper pad, but might of course be otherwise arranged.

A continuous gasket 35 extends generally perimetrically on the inner or concave face of the gripper pad to define the suction area thereof, which extends across the seal 33. The gasket 35 is of generally channel section, formed of rubber or similar material and having its open edge or side mounted in a seating base or strip 36 secured on the concave faces of the plate members 32. Secured on the concave faces of the plate members 32 in any suitable manner are elongated abutments 37 extending through at least a considerable portion of the length thereof, generally parallel to the axis of curvature, two abutment members 37 being shown as provided on each of the plate members. The projection of the abutments is not less than that of the hinge means 34 within the concavity of the gripper pads, but less than the projection of the gasket 35. Suction apertures 38 are provided in the plate members 32 to allow a vacuum pump to draw air from the suction area. The vacuum pump, not shown since it is conventional applies suction through hoses or similar flexible conduits 39 (FIG. 1) extending from the suction apertures 38, and also draws air from the reserve tanks 18 and 19 When a roll R or other cylindrical object is sealingly engaged by the gasket 35 of the gripper pad, under the control of the operator, to hold the roll R securely attached to the pad. The passages defined by the suction apertures 38 and conduits 39 are controlled by suitable valve means which may be of a type controlled by the operator, or may be automatically opened by the roll R when the gripper pad is sealingly engaged with the roll, The abutments 37 serve to space the roll R from the gripper pad 31, to provide a suction space or chamber, and also serve to limit deformation of the gasket 35 in its sealing engagement with the roll, so as to prolong its life.

As best shown in FIG. 3, the seal 33 and gasket 35 cooperate to provide a close and effective seal at the points at which the gasket crosses the joint between the plate members 32. The gasket seating strip 36 is interrupted at the joint, with its ends spaced slightly from the hinged edges of the plates, the gasket 35 continuing uninterruptedly over the space between the hinged edges. The seal 33 extends sutficiently inwardly of the concave face of the gripper pad 31 to be compressed and deformed by the gasket 35 so as to closely and completely till the space between the adjacent ends of the seating strip 36 and between the gasket 35 and the plate members.

Upper and lower (FIG. 1) pivot ribs 40 and pivot lugs 41 parallel thereto project rearwardly from the rear or convex surfaces of the plate members 32, and forwardly extending projections 42 on the mounting plate 30 each engage between a rib and lug. A pivot pin 43 extends through each pivot lug and rib and the corresponding projection 42 of the mounting plate to mount each of the plate members 32 on the plate 30 in relatively pivotable relation to each other, so that the concavity of the gripper pad may be varied to correspond generally to rolls of different diameters within a given range. The limits of this range may be defined by center stops 44 on the mounting plate 30, and outer stops 45 on the mounting plate and outer plates 32. The center and outer stops are disposed respectively inwardly and outwardly of the pivots 43, to limit swinging of the hingedly connected edges and the free edges of the plate members, respectively, toward the mounting plate. Since the curvature of the plate members 32 can correspond exactly to the circumferential surface of rolls of only one diameter, the pivotal mounting of the plate members permits relative movement thereof to accommodate rolls of other diameters, the gasket 35 effecting a proper seal against the surface of the roll. To permit of even better accommodation of the gripper pad 35 to such rolls of different diameters, at least one of the pivots 43 may be allowed a certain amount of radial movement, as by elongating the pivot apertures provided therefor in the pivot projections 42 or in the ribs 4% or lugs 41, as shown at 46 in FIG. 4. Such an arrangement permits rearward movement of the central portion of the gripper pad without effecting such a separation of the hinged plate member edges as to subject the seal 33 to substantial tensioning forces, which tend to cause failure thereof more quickly than compressive forces. Preferably, the seal 33 is formed of a width corresponding to such maximum separation of the edges, to avoid subjecting the seal to appreciable tension.

In operation, a roll of paper R or other similar cylindrical article standing on end may be picked up by moving the gripper pad 31 in vertical position, that is, with the axes of curvature of the pad extending vertically, toward the roll, as shown in FIG. 1. If the plate members of the gripper pad are in such relation to each other that the curvature of the pad substantially corresponds to the circumference of the roll, indicated by the broken line R1, the gasket 35 simply contacts the surface of the roll as the gripper pad comes into engagement therewith, without any appreciable relative movement of the plate members. Application of suction by the vacuum pump then follows upon operation of the valve means, and the roll is thus securely held by the gripper pad and may be moved as desired. As noted, since the gasket and the suction area defined by it extend across the space between the plate members, leakage is reduced because the gasket length is less than for a plurality of suction areas of the same total extent. The positions of the plate members 32 normally will be such as not to conform to the diameter of the roll. If the curvature of the roll is less than that of the gripper pad, as indicated by the broken line R2 in FIG. 4, the central portion of the gripper pad will engage the roll and continued movement of the gripper pad will result in its central portion moving rearwardly relative to the mounting plate 30, causing the plate members to swing about their pivots 43 to bring the curvature of the gripper pad into general conformity with that of the roll and effecting sealing engagement of the entire gasket 35 with the roll surface. If the roll diameter is greater than that corresponding to the curvature of the gripper pad, as indicated by the broken line R3 in FIG. 4, the outer edges of the plate members 32 come into contact with the roll surface, and as the forward movement of the pad continues the plate members swing about their pivots 43 to effect forward movement of the central portion of the gripper pad relative to the mounting plate 30, until the curvature of the gripper pad substantially corresponds to that of the roll, and the entire gasket 35 is in sealing engagement with the roll surface. If the direction of approach of the gripper pad to the roll is not head on, the gripper pad may pivot as a unit about the pivots 28 as the free edge of one or the other of the plate members engages the roll, so as to bring the pad into the desired contact with the roll. If the roll is lying on its side instead of standing on end, the operation is substantially as has just been described, except that the gripper pad is turned to a position in which the axes of curvature of the plate members are substantially horizontal.

The form of the invention illustrated in FIG. 5 is gen erally similar to that of FIG. 4. The gripper pad 31 is substantially the same as in the previously described construction, but omits the hinge means 34, the spaced opposed edges of the plate members 32 being hingedly connected only by the seal 33. Pivot ribs 50 and lugs 51 generally similar to the ribs 40 and lugs 4! project from the rear faces of the plate members 3-2, and are pivotally connected to the pivot projections 42 of the mounting plate 30 by pivots 52, so as to mount the plate members for relative pivotal movement. In addition, the pivot axes of both plate members are in this case fixed, no provision being made for radial shifting of either. The pad of FIG. 5 differs from that of FIG. 4 basically in that the opposed edges of the plate members 32 in normal or intermediate position, i.e., that in which these edges are closest to each other, lie in a common plane with the pivots 52.

By this arrangement and construction, the pivots 52 being spaced at relatively great distances from the opposed edges of the plate members, there is only relatively slight forward and rearward movement of the seal 33 relative to the plate 30 upon pivotal movement of the plate members 32, and the arcs through which the edges of the plate members move are relatively short, and do not differ very materially from straight lines, as indicated by the arcs A in FIG. 5. This fact, combined with the relaxed width of the seal 33 corresponding to the greatest separation between the plate member edges, allows the seal 33 to accommodate the movements of the plate members and the opposed edges thereof without being subject to any appreciable tensile stresses, so that long life of the seal is assured. The operation of the gripper construction of FIG. 5 is substantially the same as that described above.

In FIG. 6 there is illustrated another gripper pad construction similar to those described in connection with FIGS. 1 to 5, but differing in certain respects. The gripper construction includes a gripper pad 31 substantially as hereinbefore described, pivotally supported on a mounting plate 68 which is pivotally carried by the rotator plate 20 on an axis substantially perpendicular to that of the pivotal connection of the gripper pad on the mounting plate. A gimbal arrangement is thus provided which eliminates the gimbal frame 26 of FIG. 1. The mounting plate 60 is provided with outwardly extending trunnions or pivot studs 61 journaled in the pivot ears 27 of the rotator plate 20 to support the mounting plate 60 pivotally on the plate 20. Each of the other opposed edges of the plate 60 is provided with a pivot ear 62, extending forwardly between a pivot lug 63 and a stop arm 64 projecting from the rear face of one of the plate members 32. A pivot 65 connects each pivot ear 62 and its associated lug 63 and arm 64, thus pivotally mounting on the plate 60 the plate member 32 to which the lugs 63 and stop arms 64- are secured, on an axis perpendicular to that of the pivots 61. Each stop arm 64 extends transversely of the hinged plate member edges, and has a free end engaging with a stop bracket 66 which extends rearwardly from the rear face of the other plate member 3 2. The bracket 66 has spaced front and rear stop elements 67 between which the free end of the stop arm 64 extends. The stops 67 define the limits of swinging movement of the arms 64, and thus limit pivotal movement of the one plate member 32 in either direction.

Each pivot 65 has a portion projecting outwardly of the lug 63, or otherwise free of the pivotal connection provided by the adjacent ear 62, lug 63, and arm 64-, to provide a bearing for the central portion of the flat spring 68 the ends of which are engaged with projections or lugs 69 on brackets 70 each projecting from the rear face of one of the plate members 32. The spring 68 urges the plate members to swing toward each other, to an extreme position determined by the engagement of the stop arms 64 with the rear stop elements 67 of brackets 66. In this position, the curvature of the gripper pad 31 substantially conforms to that of the roll of smallest diameter intended to be handled by the gripper construction.

The operation of the gripper construction illustrated in FIG. 6 differs slightly from that heretofore described. If the gripper is employed with the smallest diameter roll for which the construction is designed, movement of the gripper pad 31 toward and against the roll results in close contact of the gasket 35 on the roll surface, without any appreciable relative movement of the plate members 32, and suction may then be applied as previously explained.

A roll of smaller diameter, of course, cannot be picked up by the gripper pad. If a roll of larger diameter is to be handled, as indicated at R3, engagement of the gripper pad with the roll and continued forward movement of the pad cause the outer or free edges of the plate members 32 to be spread apart, the plate members pivoting against the force of the spring 68, until the curvature of the gripper pad conforms generally to the circumferential surface of the roll. When this point is reached, the seal established by the gasket allows application of suction to secure the roll to the gripper pad. Opening or spreading movement of the plate members 32 with a roll of larger diameter is limited by swinging of stop arms 64 counterclockwise as viewed in FIG. 6 into engagement with the forward stop elements 67.

Only one of the plate members 32 is pivoted on and directly supported by the mounting plate 60, the other being supported from the one plate member by the hinge means 34. This reduces the number of parts required for the gripper construction, while permitting pivoting movement of the plate members relative to each other, and also pivotal movement of the gripper pad as a unit relative to the mounting plate 60, to allow for off-center movement of the gripper pad into engagement with a roll or similar cylindrical object.

As has been pointed out, the curvature of a gripper pad can correspond exactly to the circumferential surface of only one size of roll, although it may conform sulficiently closely to the surfaces of different size rolls to handle a range thereof. By employing more than two plate members, a closer approximation. to a number of different diameters of rolls can be provided, as will be obvious. Structural complication and cost limit the practical number of plate members which may be used.

In FIGS. 7 and 8, there is illustrated a form of gripper construction employing three plate elements instead of two. In this construction, the gripper pad is indicated generally at 80, and comprises three plate members 32 substantially identical to those previously described, arranged in side-by-side or edge-to-edge relation, the central plate member being connected to each of the end or outer plate members by hinge means 34, so that each plate member may swing relative to the others, the seal means 33 being provided between each pair of adjacent plate members. The gasket 35 and the abutment members 37 are provided substantially as in the previous constructions, a suction area sealed along its perimeter by the gasket extending continuously across both seals 33. A mounting plate 81 is provided for supporting the gripper pad on the rotator plate 20 in gimbal fashion substantially as in the case of the mounting plate 60, having pivot studs 82 journaled in the pivot ears 27 of the rotator plate 20. At each of its other pair of opposed edges, the mounting plate 81 is provided with a rearwardly extending pivot ear 83. Pairs of lugs 84 project rearwardly from the rear surface of each of the end or outer plate members 32 for pivotal support of a generally V-shaped pivot yoke 85 extending rearwardly and having an indentation or cutout 86 in its forward edge for a purpose later explained. A pivot 87 connects each yoke to one of the pivot ears 83 of the mounting plate. The opposite ends of the pivot yokes 85 are pivotally connected to the respective lugs 84 by pivots 88, the outer plate members 32 thus being pivoted on the yoke members 85 for swinging movement relative to each other and to the center plate member. The pivots 88 pass through elongated holes 89 in the yokes to allow shifting of the pivot axes defined by the pivots 88, and hence adjustment of the pivoted positions of the plate members 32, in accommodating to rolls of different diameters.

Secured on the rear face of the center plate member 32 and extending rearwardly in overlying relation to the yokes 85 and pivot cars 83 are pivot ribs 90, each connected to the adjacent yoke 85 by parallel links 91 and 92. The link 9 1 is pivotally connected to the pivot yoke 85 at one side of the center thereof by a pivot 93 which may be a stud projecting from a boss 94 on the yoke 85. The other end of the link 91 is connected to the pivot rib 90 as by a pivot pin 95 which in the position of the parts shown in FIG. 7 is almost in alignment with the pivot 87. The other link 92 is pivotally connected at one end to the yoke 85 by a pivot pin 96, and to the rib 90 by a pivot pin 97, which extends through the cutout 86 in the yoke to engage in the link 92. The parallel links allow the ribs 96, and hence the central plate member 32 and the gripper pad as a unit, to shift rearwardly and forwardly relative to the mounting plate S t, but only in the common plane of the pivots 95 and Q7. This movement, of course, differs from that permitted the outer plate members by the pivots 88. It will be understood that the yoke 85 allows the gripper pad 80 to pivot as a unit to allow for an off-center approach to a roll of paper or the like.

Bosses 98 are provided on the rear face of the central plate member 32 for engagement by plungers 99 urged forwardly by springs 160, each carried in a housing 101 secured on the mounting plate 81. The springs urge the plate members of the gripper pad to a position cor-responding to the circumferential curvature of the largest diameter roll for which the gripper construction is designed, illustrated in the full line position shown in FIG. 7. This position is determined by engagement of the pivots 88 against the inner ends of the elongated apertures 89. If a roll of corresponding diameter is engaged by the gripper pad 80, sealing contact by the gasket 35 is established without any appreciable movement of the plate members 32 relative to each other, as indicated by the broken line Rd. If a roll of a smaller diameter is to be picked up by the gripper construction, such being indicated by the broken line R2 in FIG. 7, the central plate member 32 is moved rearwardly relative to the mounting plate 81 by the roll, causing the outer plate members to pivot about the axes of the pivots 88 to bring them into contact with the roll surface, so that the gripper pad 80 substantially conforms to the smaller roll. The limit of this pivotal movement is determined by engagement of pivots 88 with the outer ends of the pivot yoke apertures 89. The movement of the central plate member 32 is directly toward the mounting plate, and since it acts in effect as a rigid link betwen the outer plate members, the latter could not pivot to give the gripper pad a more acute curvature, if it were not for the elongated holes 89, which permit the pivots 88 to move laterally outwardly and thus allow the free edges of the outer plate members to swing inwardly toward each other. From the foregoing, it will be apparent that the pivots 88 and the apertures 89 serve as stop means which limit the relative pivotal movement of the plate members 32 to a generally arcuate curvature of minimum and maximum radius setting the limits of the range of roller sizes which may be handled by the gripper construction.

It will be understood that the embodiments of the inventive concept illustrated herein are exemplary and not exhaustive, and that the invention is not limited to such embodiments, since modifications and variations thereof may be made through a wide range without departing from the spirit and scope of the invention as set forth in the appended claims.

I claim:

1. A suction gripper construction for handling paper rolls or like generally cylindrical objects comprising a mounting base, a gripper pad carried by said base in cluding a plurality of curved plate members each having at least one edge generally parallel to the axis of curvature thereof arranged in spaced opposed relation to such edge of an adjacent plate member, sealing means secured to the edges of each pair of said opposed edges substantially throughout the length thereof in such a manner that the sealing means is yieldnbly compressed between the opposed edges in all of the operational positions thereof for maintaining a suction seal between said adjacent plate members while allowing relative pivotal movement of the plate members to accommodate paper rolls or like cylindrical objects of different diameters, and a gasket projecting from the concave surfaces of the plate members and defining a suction area extending across at least one pair of said edges.

2.. A gripper construction as defined in claim 1, including means supporting the gripper pad on the base allowing movement of a central portion of the gripper pad substantially perpendicularly toward and from the mounting base.

3. A gripper construction as defined in claim 1, including hinge means for relative pivoting of at least one pair of adjacent plate members providing a pivot axis therefor adjacent and substantially parallel to the corresponding pair :of opposed plate member edges.

4. A gripper construction as defined in claim 1, including a spring means biasing the plate members to predetermined pivotal positions relative to each other.

5. A paper roll or like suction gripper construction comprising a mounting base, a gripper pad including a plurality of plate members each having at least one edge arranged in spaced opposed relation to a corresponding edge of an adjacent plate member, means for pivotally supporting the gripper pad on said base allowing relative pivotal movement of the plate members to accommodate objects of different sizes, flexible sealing means secured to the edges of each pair of said opposed edges substantially throughout the length thereof in such a manner that the sealing means is yieldably compressed between the opposed edges in all of the operational positions thereof for maintaining a suction seal between said adjacent plate members while substantially untensionedly accommodating the greatest separation thereof, and a resilient gasket projecting from the forward surfaces of the plate members and defining a suction area extending across at least one pair of said edges.

6. A gripper construction as defined in claim 5, in which said supporting means include means allowing movement of the central portion of the gripper pad substantially perpendicularly toward and from the mounting base.

7. A suction gripper construction for handling paper rolls or like generally cylindrical objects comprising a gripper pad including a pair of curved plate members each having an edge substantially parallel to its axis of curvature, said plate members being disposed with said edges in spaced opposed substantially parallel relation to each other, means for supporting the plate members for relative pivotal movement to accommodate paper rolls or like cylindrical objects of difierent diameters, hinge means pivotally connecting the plate members along an axis adjacent and substantially parallel to said edges, sealing means secured to said edges substantially throughout the length thereof in such a manner that the sealing means is yieldably compressed between the opposed edges in all of the operational positions for maintaining a suction seal between said edges while accommodating the greatest separation of the edges in pivoting movement of the plate members, and a resilient gasket projecting from the concave faces of the plate members and defining a suction area extending across said edges.

8. A gripper construction as defined in claim 7, in which said supporting means include means allowing limited non-pivotal relative movement of the plate members.

9. A gripper construction as defined in claim 7, in which said supporting means includes means allowing movement of said sealing means in a plane substantially bisecting the space between said edges.

10. A suction gripper construction for handling paper rolls or like generally cylindrical objects, comprising a gripper pad including a pair of curved plate members each having an edge substantially parallel to its axis of curvature and disposed with said edges thereof extending in substantially parallel spaced opposed relation to each other, flexible sealing means secured to said edges substantially through the length thereof in such a manner that the sealing means is yieldably compressed between the opposed edges in all of the operational positions thereof for maintaining a suction seal between said edges, a resilient gasket projecting from the concave faces of the plate members and enclosing a suction area extending across said edges, and means for supporting the plate members for limited pivotal movement to accommodate cylindrical objects of different diameters with the respective pivot axes lying in a common plane with said edges and spaced outwardly thereof by distances such that the arcs described by said edges in said pivotal movement do not differ materially from straight lines.

11. A suction gripper construction for handling paper rolls or like generally cylindrical objects comprising a gripper pad including a pair of curved plate members each having an edge substantially parallel to its axis of curvature and disposed with said edges thereof extending in substantially parallel spaced opposed relation to each other, means for supporting the plate members for limited pivotal movement to accommodate cylindrical objects of different diameters with the respective pivot axes being fixed relative to each other substantially parallel to said axis of curvature and located outwardly of and in a common plane with said edges, flexible sealing means secured to said edges substantially throughout the length thereof in such a manner that the sealing means is yieldably compressed between the opposed edges in all of the operational positions thereof for maintaining a suction seal between said edges, and a resilient gasket projecting from the concave faces of the plate members and enclosing a suction area extending across said edges.

12. A suction gripper construction for handling paper rolls or like generally cylindrical objects comprising a mounting base, a gripper pad carried by said base including a pair of curved plate members each having an edge substantially parallel to its axis of curvature, said plate members being disposed with said edges extending in substantially parallel spaced opposed relation, hinge means for pivotally connecting the plate members adjacent and substantially parallel to said edges, sealing means secured to said edges substantially throughout the length thereof in such a manner that the sealing means is yieldably compressed between the opposed edges in all of the operational positions thereof for maintaining a suction seal between said edges while accommodating the greatest separation of the edges in relative pivotal movement of the plate members, a gasket projecting from the concave faces of the plate members and enclosing a suction area extending across said edges, and means for pivotally supporting the gripper pad on the base for swinging move ment about an axis substantially parallel to said hinge axis.

13. A gripper construction as defined in claim 12, including spring means biasing the plate members to predetermined relative pivoted positions.

14. A gripper construction as defined in claim 13, in

which said supporting means allow movement of the central portion of the gripper pad in a plane substantially 'bisecting the space between said edges, and including spring means biasing the plate members to predetermined relative pivoted positions.

15. A gripper construction as defined in claim 13, in which said supporting means is directly connected only to one of the plate members of the gripper pad and the other plate member is suppoted fom said one plate mem her by said hinge means, and including spring means biasing the plate members to predetermined relative pivoted positions.

16. A suction gripper construction for handling paper rolls or like generally cylindrical objects comprising a mounting base, a gripper pad including a plurality of curved plate members each having at least one edge substantially parallel to its axis of curvature, said plate members being disposed with such edges of adjacent plate members in substantially parallel paired opposed relation, hinge means for pivotally connecting adjacent plate members along an axis adajacent and substantially parallel to said edges thereof, sealing means secured to the edges of each of said paired edges substantially throughout the length thereof in such a manner that the sealing means is yieldably compressed between the opposed edges in all of the operational positions thereof for maintaining a suction seal between said paired edges while accommodating the greatest separation of the edges in relative pivotal movement of the plate members, a resilient gasket projecting from the concave faces of the plate members and enclosing a suction area extending across a pair of said edges, and spring means for biasing the plate members to predetermined relatively pivoted positions.

17. A gripper construction as defined in claim 16, in which said plurality of plate members comprises three plate members.

18. A gripper construction as defined in claim 16, including means supporting the gripper pad on the base for movement of the central portion of the gripper pad sub stantially perpendicularly of the base.

19. A gripper construction as defined in claim 16, in which said plurality of plate members comprises at least three plate members, and including means supporting the plate members on the base for movement to relative pivoted positions for adjusting to rolls or like objects of various diameters.

References Cited UNITED STATES PATENTS 3,147,872 9/1964 Olson 214652 3,227,482 1/ 1966 Harris 2'14-650 3,276,611 10/1966 Horton 2l4-650 2,942,561 6/1960 Cheshire 49-383 X GERALD M. FORLENZA, Pliimary Examiner. HUGO O. SCHULZ, Examiner. G. F. ABRAHAM, Assistant Examiner. 

